problem with deploying mendix app on cloud foundry with postgres DB

How and wer to set the database url    WARNING: You should provide a DATABASE_URL by adding a database service to this application, it can be either MySQL or Postgres If this is the first push of a new app, set up a RL' Traceback (most recent call last):   File "/tmp/buildpackdownloads/063299c9588a0e1d380502ed03d75f37/bin/compile", line 269, in <module>     preflight_check()   File "/tmp/buildpackdownloads/063299c9588a0e1d380502ed03d75f37/bin/compile", line 97, in preflight_check     raise Exception('Missing environment variables') Exception: Missing environment variables Failed to compile droplet: Failed to compile droplet: exit status 1 Exit status 223 Staging failed: STG: Exited with status 223 Stopping instance ff48f63e-e6b1-413a-b824-cae7e2f2154b Destroying container Successfully destroyed container FAILED
1 answers

Databases are provided as a service on the CloudFoundry platform. To create one, bind a database service from the marketplace
After that, restage your app and it will connect to the database.

See the documentation of the buildback for an example.
Also, check the specific documentation for the cloud foundry implementation that you are using.